1,720,979 research outputs found
Spray deposition in “tendone” vineyards when using a pneumatic electrostatic sprayer
No full textThe objective of this study was to evaluate the effect of the electrostatic charge on foliar spray deposition in an Apulian “tendone” vineyard using an innovative pneumatic electrostatic sprayer. The sprayer was fitted with nozzles that linked the pneumatic atomization of the liquid, obtained using compressed air, to the electrostatic induction charge, thereby producing a stream of charged fine droplets. Furthermore, the sprayer was designed for low volume treatments, and the experimentation was carried out during a phenological stage with high leaf density to evaluate the performance of the machine under particularly challenging operative conditions.
The sprayer was studied at three forward speeds (4, 5, and 6 km/h), and gave poor deposition inside the canopy, whether or not the electrostatic system was activated. Forward speed did not significantly affect the mean foliar spray deposition, whereas activation of the electrostatic system significantly increased the deposit only on the layer of foliage nearest to the sprayer (lower layer), but had no effect on deposition on the layer of foliage inside the canopy (upper layer). The ratio between the deposits on the two layers (lower:upper) was 6.5:1 when the electrostatic system was switched off, and 9.0:1 when it was switched on.
However, this behaviour may allow targeted treatments on grapes, such as Plant Protection Products (PPP) or bio growth stimulants. Furthermore, the small droplets produced by the machine are suitable for table grape protection because the droplets do not mark the grapes, which would reduce the quality of the product and its commercial value
MESSA A PUNTO DI UNA METODOLOGIA DI PROVA E DELLA RELATIVA ATTREZZATURA PER IL CONTROLLO FUNZIONALE DELLE IRRORATRICI PORTATE DIRETTAMENTE DALL'OPERATORE
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MACCHINE E LORO REGOLAZIONI PER UNA DIFESA SOSTENIBILE DELLE COLTURE PROTETTE
No full textL’ottenimento di una buona efficacia da parte di un agrofarmaco dipende, oltre che dalla scelta appropriata del prodotto e dal momento di applicazione, anche e soprattutto dalla modalità con la quale avviene la sua distribuzione. Una regolazione dell’irroratrice aumenta la qualità del trattamento permettendo una corretta distribuzione degli agrofarmaci: oltre che migliorare l’efficacia, riduce la dispersione di prodotto
nell’ambiente e la quantità di miscela fitoiatrica che rimane nel serbatoio. Tutto ciò è di particolare importanza nei trattamenti alle colture protette, dove risultano elevati sia il
numero di interventi fitoiatrici, sia i rischi per l’operatore e l’ambiente in generale.
Con l’obiettivo di ridurre la contaminazione ambientale, quella del prodotto vegetale finale e i rischi per la salute dell'operatore che possono derivare dalle operazioni
necessarie per la difesa delle colture orticole protette, e anche con lo scopo di seguire le indicazioni dell'Unione Europea mirate ad incentivare una produzione agricola a ridotto impatto ambientale (Reg. 1257/99) è stato proposto e finanziato dal Ministero dell’Università e della Ricerca (MIUR) uno specifico PRogetto di Interesse Nazionale (PRIN).
La finalità di tale progetto di ricerca, al quale hanno partecipato le Università di Torino,
Padova, Pisa, Bari e Catania, erano quelle di:
• individuare le macchine e le modalità operative attualmente in uso e quelle più idonee per una coltivazione sostenibile degli ortaggi in tunnel o in serra;
• sviluppare una metodologia di prova e le attrezzature necessarie per consentire il controllo funzionale e la taratura periodica delle macchine irroratrici impiegate su tali colture;
• divulgare agli utenti le conoscenze circa i criteri di scelta e impiego di tali macchine.
I risultati ottenuti nel corso del biennio di sperimentazione si ritiene abbiano consentito:
• di ottenere una precisa fotografia della situazione esistente nel settore delle macchine per i trattamenti alle colture protette;
• di individuare le soluzioni tecniche ed operative in grado di migliorare la qualità della distribuzione, ridurre le perdite di prodotto e garantire una migliore sicurezza per l’operatore e l’ambiente in generale;
• fornire dei primi strumenti operativi per migliorare lo stato di
funzionamento delle macchine irroratrici attualmente impiegate nel settore quali la definizione di una metodologia di prova e della strumentazione necessaria per il loro periodico controllo funzionale
Drop Size Measurement Techniques for Agricultural Sprays:A State-of-The-Art Review
Full text linkPlant protection control based on the spray application of plant protection products is a very complex task depending on a series of factors, among which droplet size is the most influential for deposition and pesticide effectiveness. In fact, the adoption of the correct droplet size can ensure that the required dose reaches the target area and is not wasted, minimizes the off-target losses due to evaporation, drift and run-off and, at the same time, enhances the operator’s safety in terms of inhalation, ingestion and dermal exposure. In this paper, after defining some mean characteristic diameters helpful for a description of a drop population and focusing on the main drop size distribution functions for the statistical characterization of sprays, a critical analysis of known methods, both intrusive and non-intrusive, for drop size measurement is carried out by reviewing the literature. Among intrusive methods, the liquid immersion method and the use of water-sensitive papers are discussed, whereas, among non-intrusive methods, laser-based systems (laser diffraction, phase Doppler particle analysis) and high-speed imaging (shadowgrapy) are presented. Both types of method, intrusive and non-intrusive, can be used in machine-learning-based approaches exploiting regression techniques and neural network analysis
Improvement in pesticide application on greenhouse crops: results of a survey about greenhouse structures in Italy
No full textHorticultural crops in Italy are grown on about 33,000 hectares under frame. This type of cultivation, in plastic tunnel or in glasshouse, due to its peculiar conditions, is a very specific agro-system where diffusion of diseases and weeds is very likely. Therefore this cultivation system marks itself out because of a very high pesticide consumption, leading to heavy problems for the operator security. Therefore the choice of the type of sprayer and its way of use should be made taking into account some parameters, among other things the type of greenhouse. Within the framework of the Research Project about pesticide application in greenhouses started in 2005, a survey was taken about the situation of under frame cultivation in Italy. This was made by means of questionnaires which were filled up at 184 greenhouse growers in six Italian regions where under frame cultivation is very important. The survey regarded many features of the farms, and among them the type of structures. The results of the surveys pointed out the presence of a wide variety of types of structures, plants and spraying equipments; in particular, the most common type of structure resulted the multiple tunnel with plastic coverage fitted on an iron framework
The relationship between vertical spray patterns from air-assisted sprayers and foliar deposits in vine canopies
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A Brief Review of Nozzle Spray Drop Size Measurement Techniques
No full textSpray application of Plant Protection Products (PPP) is affected by many factors, among which drop size distribution is the most important. In fact, the correct spray spectrum ensures the required dose on the target, minimizes off-target losses due to evaporation, drift and run-off, and enhances the operator safety in terms of inhalation and dermal exposure. This study reports a brief review of the most common drop size measurement techniques present in the literature
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